Mono Lake Food Web
Warm up
 What is an ecosystem?
 What is a community?
 One of the main points about an ecosystem is the
interaction between biotic and abiotic factors.
 A community is groups of populations interacting with
one another.
Mono Lake
 One way the organisms in the Mono Lake system interact is
by eating each other. (Nom, nom….Lunch!)
 This is called a feeding relationship.
 I have sets of cards of important organisms from Mono
Lake.
 Each card contains:
 Photo
 Common and scientific name
 Life cycle and population dynamics
 How it gets food
 It’s role in the ecosystem
Mono Lake Cards
 Read the cards to become familiar with the organism.
 Organize the cards, picture side up.
 Use the arrow strips to show feeding relationships
between the organisms. (Who eats who?)
 Every organism should be included in this chart.
 If an organism is involved in more than one feeding
relationship, indicate that with arrows.
Arrow Direction
 Do spiders and flies have a feeding relationship?
 Yes
 Who gets eaten?
 The spider eats the fly
 Fly
Spider
 The arrow goes from the fly to the spider even though
the spider eats the fly. The arrow represents the energy
of the fly going into the spider.
Food Chain
 In an ecosystem, many organisms survive by eating
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other organisms.
The benefits of the food eaten by one organism can
then move to one and then another organism as each
one is eaten.
The path that food takes from one to another organism
is called a food chain.
Here is one I saw in your groups:
Planktonic aglae
Brine shrimp
California Gull
Coyote
Food Web
 I saw lots of organisms in your groups that were
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connected by more than one arrow.
Some organisms like phalaropes eat more than one
organism.
Some organisms like brine shrimp are eaten by many
organisms.
When you connect all the arrows, the arrows cross
each other in complicated ways.
A diagram that shows all the feeding relationships is
called a food web.
Types of Organisms
 What types of organisms do not eat other organisms?
 The two kinds of algae
 How do they survive with out eating?
 All living things need food/energy to survive, so they
must make their own.
 Organisms that make their own food are producers.
They make food that is consumed in an ecosystem.
 In the Mono Lake ecosystem, the producers are algae.
Types of Organisms
 Producers like algae make their own food, but animals
like brine shrimp and gulls do not.
 How do they get their food?
 They eat other organisms.
 Organisms that eat other organisms are called
consumers.
Types of Consumers
 Consumers that eat producers are primary or first-
level consumers.
 Consumers that eat primary or first-level consumers
are secondary of second-level consumers.
 Consumers that eat secondary or second-level
consumers are tertiary or third-level consumers.
 Consumers that eat tertiary or third-level consumers
are fourth-level consumers.
 And so on……..
Another Type of organism
 Some things never get eaten.
 They die natural deaths.
 These dead organisms are broken down and consumed
by microorganisms called decomposers.
 Bacteria and fungi are decomposers.
 Everything that is not eaten by a consumer is
eventually eaten by a decomposer.
Revisit your Food Web
 This time show the LEVEL of the organisms in your
web.
 Producers on the bottom.
 Primary consumers are the next level up, etc…
Some are Tricky
 Red-necked phalaropes
 Eat both brine shrimp and brine flies making them secondary
consumers.
 Also eat planktonic algae making them primary consumers.
 California gulls
 Eat mostly brine shrimp and flies.
 Given the chance will eat eggs and chicks of snowy plovers
and Caspian terns.
 How can we show these dual roles on our charts?
 What about decomposers? How should we show them?
Finish up
Lab sheet 21.